Blessed with abundant lakes and rivers, a significant part of the Ozarks' economy floats upon these waters in the form of tourism, fishing, and recreation. Water quality is very important to both economic and environmental health. Good water quality in nearby Table Rock Lake and its tributaries, the James River and Wilson's Creek, is a concern to the Citizens of Springfield. Protecting and enhancing the water quality of the James River Basin is a high priority of the City. Reduction of phosphorus in wastewater treatment plant discharge and in storm water runoff entering the area's streams is a major step in the City's efforts to reach this goal.
What is Phosphorus?
As a naturally occurring nutrient, phosphorus is a desirable part of healthy bodies of water. Similarly, algae are an important aspect of these water systems as a significant food source for aquatic life, including fish. However, a proper balance in phosphorus levels is important to provide beautiful lakes which provide good fishing. Higher than normal phosphorus levels are a primary cause of excessive algal growth, threatening the water quality of Table Rock Lake as well as other area lakes and streams.
Sources of Phosphorus
There are several sources of phosphorus in the Ozarks, both point and non-point. Non-point sources are those that cannot be traced back to a specific point of discharge. A variety of situations can be non-point sources. Phosphorus is a naturally occurring element in soils and thus is carried along when soil erodes from sparsely vegetated areas such as building sites and stream banks. Other situations include agricultural runoff of field fertilizers and animal manure, and storm water runoff from residential and commercial lawns that have been fertilized. Locally, the Show-Me Yards and Neighborhoods Program addresses the problem of lawn fertilizer. Wastewater treatment plants can be major point sources of phosphorus. Prior to completion of phosphorus removal facilities, it is estimated that the treated wastewater discharged by Springfield's Southwest Wastewater Treatment Plant contained approximately 27% of the phosphorus entering Table Rock Lake. The other 73% was from other treatment plants and agricultural/urban runoff.
The Missouri Department of Natural Resources has determined a Total Maximum Daily Load (TMDL) for phosphorus in the James River. The development of a TDML program is federally mandated for bodies of water that do not meet state water quality standards. The TDML outlines a plan to address point and non-point source pollution and includes a calculation of amounts of specific pollutants that can enter a body of water without impairing it to below standards. This program aids Springfield in determining necessary actions so that public money is spent effectively.
Following is a short history of the City's phosphorus reduction efforts. View a graph of the phosphorus removal progress at the Southwest WWTP from 1992-2010.
- 1993: $30 million in improvements to the Southwest Wastewater Treatment Plant. Result: increased efficiency and phosphorus discharged reduced by 40%.
- August 1995: City Council enacted an ordinance limiting the use of household laundry detergents containing phosphorus over a certain level. The ordinance was designed to serve as a tool to educate residents and businesses about the positive effects of reducing phosphorus levels entering the sewage collection system and what the community can do to help.
- August 1997: Council approved project increased phosphorus removal by 25% at the Southwest Plant. Cost: approximately $1.9 million, paid from sewer revenues.
- 1999: Missouri DNR and local watershed groups and stakeholders discussed phosphorus discharge from wastewater treatment plants. Results: Missouri Clean Water Commission adopted a rule change lowering allowable levels of phosphorus release by wastewater treatment facilities in the Table Rock Lake Basin. The new levels apply to facilities discharging more than 22,500 gallons per day. A phased schedule of compliance dates runs through Nov. 30, 2007. The City moved forward voluntarily to accomplish the task ahead of the deadline of Nov. 30, 2003 set for the Southwest Plant. The new facility that reduces average phosphorus discharge levels to 0.5 milligrams per liter was completed in March 2001.
- July 2002: Joint efforts by the City and DNR resulted in the City being the first in the state to receive its permit for a Municipal Separate Storm Sewer System. This permit will aid in reducing phosphorus levels in area lakes and streams by addressing storm water runoff from urban and residential areas.
- September 2002: City Council approved funding and a design contract for the expansion of the Northwest Wastewater Treatment Plant including phosphorus removal to 1.0 milligram per liter. This level of removal can be achieved biologically, without the use of chemicals. The design and construction period is expected to be about two and one-half years with a cost of $10 to $12 million.
In recognition of the importance of clean and scenic waterways to the citizens of Springfield and the surrounding area, the City will continue with efforts to reduce excess phosphorus levels. Raising public awareness of this issue is essential to increasing local support of these efforts and fostering environmentally responsible choices by citizens.